How to merge js files?

Question

JavaScript

Good afternoon!
I'm working on optimizing the frontend of the project (js). Merged all js files into two (libs.js and pages.js).
I use jquery and jquery ui. (lib.js)
Question: should these rather heavy libraries be placed in libs.js, or loaded separately (for example, cdn)?
Libs.js in production weighs 500kb + -
Thanks in advance :)

Answer 1

You say, do you use jQ-UI completely or only two or three modules?